Enhanced detection of visual targets on the hand and familiar tools
Section snippets
Participants
Thirty-two naïve volunteers (16 males and 16 females) from The University of Western Ontario took part in this study for class credits. All of the volunteers reported normal or corrected-to-normal visual acuity and were right-handed. The experiments were approved by the local ethics committee and all participants gave written informed consent.
Apparatus
In the Real Hand (RH) condition, the participants were asked to sit at a table with their head placed on a chinrest. Their left forearm was placed on the
Results
Because the order of experimental conditions within testing sessions was counterbalanced across participants, we felt that the most efficient way to analyze the data was to compute the mean RT across the 20 trials in each condition for each participant. Outliers that were more than two SDs beyond the original mean were not included in the computation of the final mean. Eliminated trials represented on average less than 2% of the total number of trials. All post hoc tests were
Discussion
Our results provide strong support for the idea that the detection of visual stimuli is enhanced when those stimuli are viewed on the surface of the hand. In other words, the participants in our study showed shorter reaction times for visual targets projected onto their own hand than they did for the same targets projected onto either a fake hand or a small garden tool. In fact, in a control experiment, we showed that detection of targets projected on a tool was no different than detection of
Conclusion
In this study, we found that visual stimuli are detected faster on one's own hand than on a fake hand or tool. Unlike visual guidance of pointing, simple visual detection is not better on skin with higher tactile-receptor density. After training with the fake hand or the tool, detection improves for targets presented on those objects. These findings provide strong support for the ‘body-view enhancement effect’ and the idea that this effect can be modulated by training such that new objects can
References (30)
- et al.
Vision in the palm of your hand
Neuropsychologia
(2009) - et al.
Koniocellular projections and hand-assisted blindsight
Neuropsychologia
(2008) - et al.
A hand in blindsight: Hand placement near target improves size perception in the blind visual field
Neuropsychologia
(2008) - et al.
Direct evidence from parietal extinction of enhancement of visual attention near a visible hand
Current Biology
(2000) - et al.
Extension of corticocortical afferents into the anterior bank of the intraparietal sulcus by tool-use training in adult monkeys
Neuropsychologia
(2006) ‘Action binding’: Dynamic interactions between vision and touch
Trends in Cognitive Sciences
(2001)The signaling of touch, finger movements and manipulation forces by mechanoreceptors in human skin
- et al.
Reaching with a tool extends visual-tactile interactions into far space: Evidence from cross-modal extinction
Neuropsychologia
(2001) - et al.
Tool-use changes multimodal spatial interactions between vision and touch in normal humans
Cognition
(2002) - et al.
Visual processing and the bodily self
Acta Psychologica
(2008)
Rubber hands ‘feel’ touch that eyes see
Nature
Improved visual sensitivity in the perihand space
Experimental Brain Research
That's my hand! Activity in premotor cortex reflects feeling of ownership of a limb
Science
Dynamic size-change of hand peripersonal space following tool use
Neuroreport
Coding of peripersonal space in inferior premotor cortex (area F4)
Journal of Neurophysiology
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2021, Consciousness and CognitionCitation Excerpt :At the behavioral level, researchers found another index of tool embodiment in the increased efficiency by which the sensorial stimuli close to the end of the tool are processed. For instance, a study by Kao and Goodale (2009) investigated whether the simple detection of visual stimuli on external objects improves when people are trained to use them as tools. Participants performed a speeded visual detection task (they were asked to press a button as soon as they saw a light) to targets presented on either own hand or external objects (a fake hand and a small rake).
Hand function, not proximity, biases visuotactile integration later in object processing: An ERP study
2019, Consciousness and CognitionCitation Excerpt :Additionally, experience or expertise with the hand or tool also appear to be necessary for proximity effects (Brown, Doole, & Malfait, 2011; Gozli & Brown, 2011; Iriki, Tanaka, & Iwamura, 1996; c.f., Maravita, Spence, & Driver, 2003). Kao and Goodale (2009) demonstrated that their tool-use facilitation effects occurred only when participants were trained to use the tools and visual stimuli were projected on the functional parts of those tools. In sum, hand- and tool-use effects are not automatic exclusively because of proximity and sensory processing; rather, functional experience appears to be necessary in facilitating this process.
Phantoms on the hands: Influence of the body on brief synchiric visual percepts
2016, NeuropsychologiaCitation Excerpt :More recently, a number of studies with neurologically intact individuals have found evidence not only for the existence of peripersonal representations, but that visual stimuli in peripersonal space are processed differently from visual stimuli away from the body (e.g. extrapersonal space). Differential effects for processing visual stimuli near versus far from the hands have been observed for a number of visual attention tasks (Abrams et al., 2008; Cosman and Vecera, 2010; Davoli et al., 2012a; Reed et al., 2006), change detection (Tseng and Bridgeman, 2011), visual perceptual grouping (Huffman et al., 2015), visual memory (Davoli et al., 2012b), visual sensitivity (Dufour and Touzalin, 2008), visual target detection (Kao and Goodale, 2009), and temporal fusion in object substitution masking (Goodhew et al., 2013). It has been hypothesized that the processing of visual space around the body may be associated with specific visual pathways.